Transcript File - ELECTRONICS CLUB

Cadsoft Eagle Tutorial
Objectives
• Recognise the difference between Through Hole Parts
(THP) and Surface Mount Devices (SMD)
• able to create a new project folder
• create a new schematic file
• add and remove library files from Eagle
• search for and add parts to a schematic
• set part names and set values
• Use Electrical Rule Check (ERC) to search for and correct
errors in schematic
• Translate schematic to board layout
• Create a ground plane
• Manually route airwires to tracks
Running Eagle for the first time
• Upon running Eagle, you will see a screen very
similar to the one below.
Creating a new project
• Where it says "Projects“ Click the triangle to
the left.
• Left-click on the "eagle" folder, then right-click
to bring up a menu. Choose "New Project".
• Name your project whatever you'd like.
Creating a new schematic
• Eagle projects are made of two main files, a
schematic file (.sch file extension) and a board
file (.brd file extension.
• Right click on your project folder and select
"New Schematic".
• It will automatically open a blank schematic
window.
Creating a new schematic
Creating a new schematic
Creating a new schematic
• You can then save this blank schematic. This
will create a schematic file for your project.
• Click on the blue diskette icon to the top left
corner and name your file.
Creating a new schematic
• For this project we will design a circuit and
board based around 555 timer chip.
• We will begin begin by collecting the parts.
• On the left side of your window click the Add
button. This button is below the paste tool
and to the right of the big black X or delete
button.
• Clicking the Add button will open a pop up
window
Creating a new schematic
Creating a new schematic
Creating a new schematic
• There are two ways to find a part you are looking for.
– The first is by typing text in the search form towards the bottom
left of the window and pressing ENTER. This will narrow down
the number of libraries in the left pane. If for some reason it
yielded no results or not the results you were looking for, clear
the text box and hit ENTER again. It will then display your full
library list again.
– The second approach is to sift through the libraries in the left
window pane. Double-clicking or click on the grey triangle will
expand the library as well as open up devices that contain
multiple packages.
– Searching for simply “555" will probably yield no results, but
"*555*" with the asterisk as a wild card will give you exactly
what you need. The search function is very literal and so using
the wild cards will be extremely helpful.
Creating a new schematic
• Once you select a part, it will populate the two panes to the
right. The one on the left will show you a preview of it as a
schematic and the one on the right will show you a preview
of it on a board.
• We're looking for a DIP/DIL (dual inline package) version
• DIP is a package type with long metal legs. They are easiest
to work with but larger than most other packages. Select it
and click OK.
• You'll now be returned to your blank schematic, except this
time you'll see a red chip moving wherever you move your
cursor.
• Click on the screen where you'd like to put it.
Creating a new schematic
Creating a new schematic
• After clicking once you'll notice that the 555 chip is still
stuck to your cursor. Press the ‘Esc’ key on your keyboard
once to get rid of it, and to bring you back to the ADD part
window.
• We’ll add the rest of the parts before continuing
– Search for and add 1 each of the following to the schematic
•
•
•
•
•
•
•
1N4004
R-EU_0207/10 (Resistor)
CPOL-EUE2.5-6 (capacitor)
C-EU050-025X075 (capacitor)
VCC
GND
WIREPAD 2,54/1,0
Creating a new schematic
• Before we start wiring, we will briefly go over some
really helpful tools.
– These tools are located on the top toolbar towards the
center. They are for zooming in and out of your schematic.
• The button on the far left is a "Fit" zoom. It will zoom into your
schematic so that all the components fit in your window.
• The second one over is a basic "Zoom In" tool.
• The third over is a basic "Zoom Out" tool.
• The second from the right is a "Redraw" tool which is essentially
used to refresh the window and redraw the schematic. Use this if
the schematic appears to be showing strange artifacts or broken
pieces of the schematic.
• The tool on the far right is a "Select Zoom" tool. Click and drag to
create a box in which the window will zoom to.
Creating a new schematic
• This is the "Move" tool. It is located near the top of the left toolbar. Click
the button, click on a part, and it will then allow you to drag the part
around your schematic.
• This is called the "Rotate" tool and is located one button down and to the
right from the "Move" tool. This tool lets you rotate a part in your
schematic. Click on a part and it will rotate it 90 degrees.
• The "Delete" tool. Located towards the middle of your toolbar. When
activated, it will delete any part or electrical connection in your schematic
that you click on.
• The "Name" tool and the "Value" tool. The "Name" tool will allow you to
rename any part in your schematic. So, for example if you have a resistor
named "R1" you can change its name to "R10".
• The "Value" tool lets you annotate the value of a particular part. For
example, we placed a couple resistors into our schematic before. This will
let us assign a resistor value to them in the form of text. Click on a resistor
with the "Value" tool and then type the value you'd like to assign, for
example: 220 or 1k.
Creating a new schematic
• Arrange your parts to look like the diagram
shown below.
Creating a new schematic
• To connect all your parts together in your
schematic you will be using the "Net" tool.
• You can also select the Net tool by going to
the "Draw" drop-down menu at the top of
your screen and selecting "Net".
• DO NOT use the "Wire" tool which you may
think is what you need.
Creating a new schematic
Creating a new schematic
• Simply click the "Net" tool, then click on the
tip of the pin you'd like to start a connection
at and then click on the tip of the pin where
you'd like to complete the connection.
• The electrical connection will be bright green
at first and will turn darker green when a
connection has been successfully made.
PCB Design & Board Layout
Designing the circuit board
• With your schematic complete, to create a
circuit board from this, begin by clicking the
'Board' button on the top toolbar. It is located
between the CAM tool, and the sheet selector.
The 'Board' button contains a logic gate above
an IC or chip drawing.
Designing the circuit board
• Upon clicking the button it will ask if you'd like
to create a board file from your schematic,
you will click YES and then a black window will
open displaying all your electronic
components and a big rectangle denoting the
outline of your board dimensions.
Designing the circuit board
• First begin by moving all your components over to the
board and orienting everything the way you'd like
them. This can be done by a combination of the 'Move'
tool and the 'Rotate' tool.
• You may have noticed that a lot of the same tools you
used in the Schematic file are the same in the Board
file. So, go ahead and put everything where you'd like
them to be. It may be a good idea to keep in mind the
usability of your board.
• Also try to keep components that will be working
together close, e.g. placing components that form the
power supply adjacent to each other.
Designing the circuit board
• If you'd like to move everything over at once,
click the 'Select' tool then click and drag a
selection box over all your components.
• Once you release the mouse, it will
automatically choose the 'Move' tool for you.
Now press CTRL and right-click on one of the
components in the group and you will now
notice all the components you selected are
available to be moved at once.
Designing the circuit board
• If you notice that there is a lot of empty space.
The board is probably too large for the small
amount of components you'd like to put on it.
• Select the 'Move' tool and click on either a
side of the board dimension (the grey box) or
a corner of the board dimension and you'll be
able to adjust it.
Designing the circuit board
• You may notice there are alot of dark yellow lines
connecting everything. These are the electrical
connections you need to make. Eagle is nice
enough to keep track of all connections from your
schematic.
• Before we start running connections, lets use the
'Ratsnest' tool to have Eagle untangle everything
and compute the shortest connection to be made
with your new configuration.
• The 'Ratsnest' tool looks like this
Designing the circuit board
• Time to route our traces and complete the
electrical connections. There are two tools
that are very useful when routing traces.
• The tool on the left is the 'Route' tool that
allows you to begin laying traces and the tool
on the right is the 'Ripup' tool which lets you
delete traces you've already made.
Routing Traces
• The two options for routing traces for your board are the automatic
way and the manual way.
• In almost every situation, I recommend the manual way. The reason
is that the automatic routing in Eagle does a decent job, but a
messy one at that. And, on occasion the automatic route is unable
to route everything for you and will leave the work unfinished.
• If you want a beautiful board, do it yourself.
• If you plan to use chemical etching and don't care how messy things
look, consider the automatic routing. However if you plan to use
the mechanical PCB etching machine, only PCB’s that have been
neatly routed will be manufactured.
• Take note though, designing a circuit board with not much time to
spare can be a risky undertaking. Take your time, double-check your
work, and don't rush things.
Adding a Ground Plane
• To add a ground plane to your circuit, click on
the ‘Polygon’ tool.
• Draw a closed rectangle around the outline of
your board.
• Select the ‘Name’ tool and click on the outline
of the rectangle.
• Rename the polygon to ‘GND’ and select the
radio button beside ‘the Entire Signal‘
Adding a Ground Plane
Jumping Over Traces
• At some point you may be faced with an
airwire that you cant successfully route
without it crossing over another trace.
• This can be overcome by following the steps
below:
Autorouting
• The 'Autoroute' tool is located towards the
bottom of your side toolbar and looks like
this...
• If you click on this tool a window will open.
Autorouting
• This window is giving you the option of configuring how your Autorouter
works.
• You may ignore most of this unless you are more experienced and wish to
customize things to your liking. On the left side of the window there are
two drop-downs for Top and Bottom. These drop-downs let you configure
the direction of the traces on the top and bottom layers.
• If you only wish to do a single layer of traces, for example if you are
designing a board that you'd like to chemically etch, then turn off one of
the layers by setting it to N/A.
• If you're etching a single-sided board, turn off the top layer so your traces
will only be on the bottom.
• When done, click OK, watch it work, and cross your fingers it finishes
successfully. At the bottom left of your screen you will see a percentage
complete.